/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.connector.kafka.sink.internal;

import org.apache.flink.annotation.Internal;

/**
 * The writable portion of a {@link Backchannel} for communication between the commiter -> writer.
 * It's used to signal that certain transactions have been committed and respective producers are
 * good to be reused.
 *
 * <p>Messages can be sent before the backchannel is established. They will be consumed once the
 * backchannel is established.
 */
@Internal
public interface WritableBackchannel<T> extends Backchannel {
    /** Send a message to the backchannel. */
    void send(T message);
}
